Rotary internal-combustion engine



Jane 2, 1945. L. w. BEAVEN ROTARY INTERNAL -COMBUSTION ENGINE Filed Dec. '7, 1942 3 Sheets-Sheet 1 Jan, 2, 1945. L w. BEAVEN 2,366,478

ROTARY INTERNAL-COMBUSTION ENGINE Filed Dec. 7, 1942 3 Sheets-Sheet 2 Jan. 2, 1945. L w BEAVEN 2,366,478

ROTARY INTERNAL-COMBUSTION ENGINE Filed Dec. 7, 1942 v 3 Sheets-Sheet 3 Fla. 4.

0.0 i g o I////// mW /w latented Jan. 2, 1945 UNITED STATES PATENT OFFICE 2,366,478 ROTARY INTERNAL-COMBUSTION ENGINE Leslie W. Beaven, Chicago, Ill. Application December 7, 1942, Serial No. 468,037 2-0 Claims. (01123-44) My present invention is particularly adapted for high speed engines, preferably internal combustion rotary engines of the multiple-cylinder radial type wherein the rotating cylinders are cooled through the influence of air currents moving past the cylinders in a housing which envelops said cylinders.

In engines such as abov suggested, it has been the practice to provide a plurality of lateral fins upon the exteriors of the cylinders and cylinder heads or domes for the purpose of cooling these parts.

It is one of the objects of the present invention to simplify the construction of the engine cylinders and lighten the structure thereof by eliminating the provision of fins on the exterior of the cylinder, and at the same time provide improved means for efiiciently and effectively cooling the cylinder, and also reduce the cost of manufacture.

In the usual static radial types of airplane engines, the cylinders and heads are finned to assist cooling thereof and since the coolant air-stream velocity is limited to approximately the air speed of the airplane, the fins must be made long and numerous with the result that the Cylinder and head assemblies are heavy, bulky and complicated, as well as expensive to make.

In rotating radial engines such as that disclosed herein, the spinning cylinders have a velocity which is independent of the air speed of the plane, such velocity being substantially two to four times as great as the top air-speed of the static types of engines. It has been ascertained that this increased velocity permits the elimination of the fins entirely on the cylinder barrels and heads and thereby greatly simplify their construction, their assembly, and their cost. This furthermore materially reduces the over-all dimensions of the engine which permits the outer housing and jacket to be made of smaller sectional dimensions, and it also reduces the weight and diminishes the centrifugal stresses on the revolving crank-case permitting th crank-case to be made lighter. The whole engine structure is thereby lightened.

The lightening of the cylinders is particularly effective, since the major portion of the excess weight in the prior engines is in the heads with the result that the radius of gyration is long and the centrifugal stresses therefore high. B using anon-finned tube for a cylinder barrel and welding or otherwise securing on it a domed head of pressed plate (or other equivalent) the centrifugal stresses on the flanges and crank-case are tremendously reduced.

For this purpose it is preferred to employ metals of high conductivity in the cylinders to assist conduction of the heat through the cylinder walls, and the extraordinary volume of coolant air will effectively handle the convection of the said heat as rapidly as it reaches the outer surfaces of the cylinder walls and heads.

Where the spinning radial cylinders are arranged in a. plurality of rows in a housing with the cylinders of the respective rows disposed in staggered relation to each other, the coolant air currents created in the housing do not always travel in paths which bring them into contact with the heads and outer ends of the cylinders, and since these portions develop the highest temperatures, the cooling of the cylinders is not as effective asidesired. In order to overcome this inherent fault, I have provided improved means whereby to insure the directing of air streams against the heads and outer ends of the cylinders.

One of the objects of the present invention is to simplify the construction and improve the efflciency and operation of an engine of the kind contemplated herein.

Another object is to provide an internal combustion rotary engine which is effectively and quickly cooled.

A still further object or aim of the present invention is to provide a structure of the kind herein disclosed that is assembled from sturdy and dependable parts that are capable of withstanding heavy duty and severe usage at a high speed such as desired foran airplane engine.

The improvements which I have disclosed herein are of compact arrangement; they are exceedingly eflicient in operation; and the structure is economical to produce in that it may be made from commercially available materials.

The before-mentioned and other objects, aims, and advantages will be obvious to persons who are skilled in the art from the within description and the accompanying drawings. It is preferred to practice the invention and to accomplish the objects thereof in substantially the manner hereinafter described, and as more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a fragmentary view of a portion of an engine showing one of the cylinders and a portion of the engine casing and the outer jacket, and showing my improvements incorporated therein, the view being partly in section and partly in elevation.

Figure 2 is a vertical transverse section through the engine casing and the outer jacket, the view being of a fragmentary character with two staggered cylinders shown in elevation.

Figure 3 is an enlarged view in vertical section showing details of the engine mounting and anchoring means.

Figure 4 is a detail plan in a diagrammatic form illustrating the novel arrangement of air.

stream directer and the air control elements.

Figure 5 is another diagram similar to Figure 4 with the parts omitted.

Figure 6 is a. diagram showing the arrangement with a single row of cylinders.

The drawings are to be understood as being more or less schematic, and they disclose a typical or preferred 'form embodying this present invention.

The engine shown comprises a crank-case III that rotates upon a crank-shaft, the latter having a bore through which the fuel from a suitable source is discharged into the casing and is distributed into the cylinders of the engine. The shaft is secured at one end in the stationary outer housing or jacket l3 having the general shape of a rotary blower and the crank-case has a, plurality of openings in its cylindrical wall, at which the cylinders are mounted. In the present instance, for the purpose of simplifying the drawings, there is shown only one cylinder of a single row in Figure l, but it will be understood the cylinders are disposed in one or more rows in zigzag relation to each other as shown schematically in Figures 4 and 5.

The cylinders are formed from thin metal of a sufficient gauge and of such thickness and toughness to withstand the heavy duty to which they are subjected when th engine is in operation. As shown, the cylinder comprises a metal seamless tube l5, and its lower portion is preferably flared outwardly to provide a. lateral mounting flange it that rests upon a. boss of the crankcase I so that the axis of the cylinder is radial to the axis of the said crank-case. In order to anchor the flange i 6 in position, there is provided a heavy ring 11 having a slightly larger internal diameter than the outside diameter of the cylinder tube I that is preferably welded to the cylinder and its flange. The flange and ring are secured to the crank-case Ill by means of studs I8 which are inserted through this ring l1, and the flange l6, and are screwed into the casing wall and the parts clamped by nuts.

The outer portion of the cylinder tube I5 is preferably turned smooth on its outside surface to snugly fit into the open portion of the head 2| which latter is preferably a dome-shaped pressed plate as shown in Figure 1. This head may be hemispherical in shape, with a skirt portion is which has its inner surface 20 disposed tangent to the body portion and cylindrical in shape to provide a press fit with the outer face of the tube i5 to which it is secured by welding or otherwise. After the head 2! has been secured to the tube the outer face of the skirt I 9 may be ground to provide a tapered thickness to merge into the tube.

The head 2| is provided with an exhaust port opening 22, and the edge of said opening provides means for mounting an exhaust valve unit such as shown in Figure 2. This valve unit may comprise a somewhat bell-shaped member 23 having an open inner end which is disposed inside the domed head, said open end being provided with an annular valve seat 24 to cooperate with the valv body 25, and adjacent this seat there is a lateral outlet 23a. The bell-shaped member 23 is preferably secured in the exhaust port opening 22 by welding it in position, and it is provided with an outwardly projecting extension 26 having a central bore to receive a guide-sleeve 21 for the valve stem 25a. An exhaust stub 28 is welded or otherwise secured to and is made a part of the valve unit structure so that said stub surrounds the lateral outlet 23a and is disposed preferably with its axis oblique to the axis of the bell-shaped member 23 in the manner shown in Figure 2.

The inner surface of the tube forming the cylinder body I5 is provided with a smooth surface for the piston 29 which reciprocates therein, and the piston is provided with a feed port 30 controlled by a valve 3| for admitting the fuel to the combustion chamber of the structure. The intake valve 3| is actuated by any suitable means or mechanism which is adapted to open and close the port 30 at the proper time during the cycle of operation of the engine so that the fuel is fed into the combustion chamber where it is exploded and resultant gases therefrom are exhausted through the valve controlled exhaust port in the dome shaped head. Likewise, any suitable means or mechanism may be employed to actuate the exhaust valve 25 in a timed and synchronized relation to the operation of the engine and the fuel intake valve 3|.

Due to the relatively thin dimensions of its walls, the heat generated within the cylinder finds quick transfer to the surface of the cylinder Where it is readily dissipated and absorbed by currents of cooling air which are forced around the cylinder during the spinning of the engine.

If desired, the outer surfaces of the cylinder tube may be coated with a suitable material 2la having a higher heat conductivity than the metal of said tube. Such material may, for example, be a plating of silver, copper, aluminum, or the like, which will function to conduct the heat along the surface of the tube towards the crankcase, thereby spreading the heat over a larger area. Also, if desired, the cylinder and head may be a one-piece structure formed by a suitable die drawing operation.

It is preferred, in order to bring the air currents into intimate or close relationship to the cylinders and heads, to provide means for enveloping or housing the engine and at the same time to .increase the speed of flow of the air currents as well as to control the passage of the air through the housing. This is done by means of the in- 3| that are mounted upon the stationary supporting frame i3 before mentioned, and are spaced a suitable distance laterally from the cylinders in order to permit the engine to be rotated between said walls. The outer portions of said side walls are connected by a-concave-convex transverse wall 32 which arches over the ends of the cylinders and their associated parts, whilst the inner portions of these side-walls 3| are provided with circular inlet openings 33 which admit the outside air into said jacket for circulation about the cylinders.

Means are employed for creating air currents and for directing these air currents into contact with and around the cylinders. This comprises a housing in the form of annular plates 34, 34, between which the rows of cylinders are disposed, and said plates may be secured in position by brackets 35 anchored to the plates and attached to the engine by interposing their basal ends between the rings l1 and the nuts that are carried by the studs l8 as shown in Figure 3. These plates are of a diameter to extend into the arched portion 32 of the enveloping housing or jacket, and are arranged to provide an open space or annular outlet between them through which the air currents are discharged into the housing or jacket, whilst these plates have air-intake openings 36 of suitable diameters for proper clearance. Plates 34 have outward flares 36 at their inner margins, and if desired their body portions may be stifiened by means of annular corrugations 38, 38 as shown in Figures 1 and 2.

The annular outlet space between the outer portions of the housing plates 34 beyond the cylinders is bridged by means of oppositely disposed rows of thermo-responsive air control elements, each preferably consisting of several bi-metal units or strips which are superposed upon each other and have their outer portions, which are nearest the housing plates, preferably supported by horizontal baiiies 40 that project laterally inward from the plates 34. The elements 39 are preferably united laminae of metals having different co-efiicients of expansion, for example, one being brass and the other nickel and iron which causes the louvers to flex under temperature changes. The baifies 40 have flanges 4| which are attached to the plates 34 upon the inner surfaces of the latter. It will be thus seen that temperature changes of the air currents passing through this housing will cause a flexing of the elements 39 and thereby control the quantity of air passing through the open-ended or outlet space between the outer port ons of the housing plates 34. These elements 39, however, constitute the subject matter of one of my co-pending applications. It is preferred to arrange these elements 39 in a manner so that alternate elements will bow inwardly while the other louvers will bow outwardly under the influence of the temperature of the air streams. This is suggested by surface shading on Figure 4.

The baffie plates 40 project towards and above the domes of the cylinders and their free edges are undulated or wavy as shown in diagrammatic form in Figure 4 where it will be observed that the concave portions 40a of the wavy edge cenforms somewhat with the shape of the adjacent surfaces of the cylinders in the contiguous row, while the convex or protruding portions 40b project into the spaces between these cylinders and towards the cylinders in the other row. This shaping of the bafiies 40 is made for the purpose of directing the coolant air streams over the domes and outer portions of the cylinders so that the air streams bend and are caused to change their courses while traversing the space between the housing walls 34. In order to provide rigidity to the baffie plates 40 I prefer to brace them by means of oblique struts 49c.

The thermostatic element assemblies 39 are preferably of uniform length as shown in the diagram of Figure 4 with the result that the proximate ends of the said elements describe an undulating curve which is equidistant from the undulated edges of bafiies 40, so that said louvers will open and close, immediately beyond the centers of the respective domes 2| of the staggered cylinders. The curved path which is inscribed by the proximate ends of the elements adjacent each head is adapted to divide the area of each head substantially equally in the manner suggested by the dot-dash line on Figure 5 wherein the zone A is of approximately the area as the other zone B which thereby tends to maintain the dome surface at substantially the same temperature throughout.

The engine exhaust stubs 28 communicate with a perforated annular exhaust pipe 42 through hollow couplings 43, whereby the products of combustion, which have been scavenged from the cylinders, discharge into the stationary jacket through the perforations 42a in the exhaust pipe, and from the jacket they pass into the outside atmosphere through a tangentially disposed port 32a, a fragmental portion of which is shown in Figure 1. The means for increasing the speed of movement of the air currents through the structure is preferably in the form of a plurality of impeller blades 44 preferably of arcuate crosssection such as shown in Figure 1, that are disposed nearly radial to the axis of rotation of the" cylinders and the housing plates alongside said cylinders. These blades are located beyond the thermostatic elements 39 and they are disposed upon both sides of the exhaust tube to which their proximate inner ends may be suitably connected. The outer end portions of said blades 44 extend to and are secured t the adjacent faces of rings 45 which are attached to the outer portions of the plates 34.

The foregoing air-control structure is adapted to automatically regulate the volume of air passing through the cylinder housing between the plates 34 in proportion to the temperature of said air, and the speed of flow of such air is accelerated by the blower action of the blades 44. The fresh air drawn into the housing thus comes into intimate speedy contact with the thin walled cylinders and is particularly directed by the baffles 40 over the outer ends and heads, thereby assisting in the rapid dissipation of the heat incident to the operation of the engine.

When the engine consists of a single row of cylinders the proximate ends of the elements 39 may be in a straight line through the axes of the cylinders and heads in the manner shown diagrammatically in Figure 6, and the baffles 40 may have straight inner margins. This arrangement will be equally effective due to the fact that the thermostatically controlled elements will open to a lesser extent between the cylinder .heads and to a greater extent at the heads where open space between their outer portions beyond the heads of said cylinders; thermo-responsive closures extending across said open space to control passage of air therethrough; and baffles disposed transverse to said walls adapted to direct air streams against the heads of said cylinders.

2. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said walls providing an open space between their outer portions beyond the heads of said cylinders; thermo-respcnsive closures extending across said open space to control passage of air therethrough; and annular baflles disposed transverse to said walls and extending into said open space, said bafiles arranged to direct air streams against the heads of said cylinders.

3. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and passage or air therethrough; and bailles disposed transverse to said walls, said bafiles formed with.

an undulating edge adjacent said cylinders'to" direct air streams against the heads of said cylinders.

4. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said walls providing an open space between their outer portions beyond the heads of said cylinders; thermo-responsive closures extending across said open space to control passage of air therethrough; and annular baflles supported by and extending transversely from said walls into said open space, portions of said baflles adapted to direct air streams against the heads of said cylinders.

5. In an internal combustion rotary engine,

.radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said walls providing an open space between their outer portions beyond the heads of said cylinders; annular baflles disposed transverse to said walls adapted to direct air streams against the heads of said cylinders; and thermo-responsive closures extending from said baflies across said open space 'to control passage of air therethrough.

6. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said walls providing an open-space between their outer portions beyond the heads of said cylinders; annular bailles supported by and extending transversely from said walls into said open space, said baflles adapted to direct air streams against the heads of said cylinders; and thermo-responsive closures carried by said baflles and extending across said open space to control passage of air therethrough.

7. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from. said cylinders and movable therewith, said walls providing an open space between their outer portions beyond the heads of said cylinders; annular baffles disposed transverse to said walls, said baflies formed with undulated inner edges adjacent said cylinders to direct air streams against the heads of said cylinders; and theme-responsive closures carried by said baiiles and extending across said open space to control passage of air therethrough.

8. In an internal combustion rotary engine, a plurality of rows of radially disposed cylinders rotatable around a common,.axis and arranged in staggered relation to each other; walls spaced from said cylinders and movable therewith, said.

walls providing an open space between their outer portions beyond the heads of said cylinders; annular baflles projecting inward from said walls into said open space, the inner edges of said baffies having an undulated outline with the wider portions disposed between adjacent cylinders. said bailles adapted to direct air streams against the adjacent heads of the cylinders; and thermo-. responsive closures extending from said baffles into said open space, the proximate ends of opposing closures disposed in a manner to approximately bisect the surface areas of the cylinder heads, the said closures adapted to control passage of air through said open space.

9. In an internal combustion rotary engine, a plurality of cylinders rotatable around a common axis; housing walls movable with said cylinders between which said cylinders are disposed, the

'outer portions of said walls providing an open space between them beyond said cylinders; and bafiles projecting inward from said walls into said open space, the inner edges of said bafiles having an-undulated outline with the widest portions disposed between adjacent cylinders to direct air-streams against the radially outer portions of said cylinders.

10. In an internal combustion rotary engine,

' radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said walls providing an open-ended space between their outer portions beyond the heads of said cylinders; control means for regulating the quantity of air passing through said open-ended space; and bailles disposed transverse to said walls adapted to direct air streams against the heads of said cylinders.

11. In an internal combustion rotary engine, radially disposed cylinders rotatable around a common axis; walls spaced from said cylinders and movable therewith, said Walls providing an open-ended space between their outer portions beyond the heads of said cylinders; automatically Operable control means for regulating the quantity of air passing through said open -ended space; and bafiles disposed transverse to said walls and adapted to direct air streams against the heads of said cylinders.

12. In an internal combustion rotary engine, a plurality of cylinders rotatable around a common axis; housing walls movable with said cylinders between which said cylinders are disposed, the outer portions of said walls providing an open spac between them beyond said cylinders; control means for regulating the quantity of air passing through said open space beyond said cylinders; and baffies projecting inward from said housing walls into said open space, the inner edges of said bailles having an undulated outline with the widest portions disposed between adjacent cylinders to direct air-streams against the radially outer portions of said cylinders,

13. In an internal combustion rotary engine, aplurality of cylinders rotatable around a common axis; housing walls movable with said cylinders between which said cylinders are disposed, the outer portions of said walls providing an open space between them beyond said cylinders; thermo-responsive closures carried by and; ex-

= tending between said housing walls beyond 'said cylinders for regulating the quantity of air passing through said open space; and baifles projecting inward from said housing walls into said open space, the inner edges of said bailles having an undulated outline with the widest portions disposed between adjacent cylinders to direct airstreams against the radially outer portions of said cylinders.

14. In an internal combustion rotary engine, a plurality of cylinders rotatable around a common axis, each cylinder comprising a sheet metal tube and a pressed metal dome-shaped head secured to said tube; parallel housing walls spaced from the sides of said cylinders, said walls providing an open space beyond said cylinder heads; air-current creating means extending between said walls; control means for regulating the quantity of air passing through the open space beyond said cylinder heads; and baflles projecting inward from said housing walls and directing the aircurrents into intimate relation to said cylinder tube and across said dome-shaped heads whereby transfer of internal heat through said cylinder tubes and heads is facilitated and such heat is thereby rapidly dissipated at the outer surfaces of said tubes and heads.

15. In an internal combustion engine of the rotary cylinder type, a tubular body and a hollow end member each constructed of thin material, to facilitate the rapid transfer of internal heat therethrough to be dissipated at the outer surface thereof, the said end member and one end of the body being telescoped one with the other, and secured together, the entire outer surface thereof being free from cooling fins, the body and head end of the cylinder being unjacketed.

16. In an internal combustion engine of the rotary cylinder type, a tubular body and a hollow end member each constructed of sheet material, to facilitate the rapid transfer of internal heat therethrough to be dissipated at the outer surface thereof, the said and member and one end of the body being telescoped one with the other, and secured together, the entire outer surface thereof being free from cooling fins, the said body and the said end member being unjacketed.

17. In an internal combustion engine'of the rotary cylinder type, a cylinder, a housing within which the cylinder is disposed, said housing having an air inlet and a discharge outlet, the latter disposed adjacent and beyond the cylinder head, a baflle disposed to extend from a wall of the housing and transversely of said outlet opening for directing air streams against the head of said cylinder, and means to control the passage of air currents through said housing.

18. In an internal combustion engine of the rotary cylinder type, a cylinder, a housing within which the cylinder is disposed, said housing having an air inlet and a discharge outlet, the latter disposed adjacent and beyond the cylinder head, a baflle disposed to extend from a wall of the housing and transversely of said outlet opening for directing air streams against the head of said cylinder, and thermostatically operated elements constituting variable impediments to the air currents for controlling the flow of said air currents through the housing.

19. In an internal combustion engine of the rotary cylinder type, a plurality of cylinders, a housing within which the cylinders are disposed, said housing having an air inlet and a discharge outlet, thermostatic variable air impediment elements extending transversely of said outlet for controlling the air currents, and baflies projecting into said housing and opposed to each other, the inner edges of said bafiles having an undulated outline with the widest portions disposed between adjacent cylinders to direct air streams against the radially outer portions of said cylinders.

20. In an internal combustion engine of the rotary cylinder type, a plurality of cylinders, a housing within which the cylinders are disposed, said housing having an air inlet and a discharge outlet, thermostatic variable air impediment elements extending transversely of said outlet for controlling the air currents, and bafiies projecting into said housing and opposed to each other, the inner edges of said baiiles having an undulated outline with the widest portions disposed between adjacent cylinders to direct air streams against the radially outer portions of said cylinders, the proximate ends of adjacent air impediment elements terminating short of each other to form a passage therebetween, said passage substantially following the contour of the space between the baflles.

LESLIE W. BEAVEN. 

